is there any library which receives requests, sends response & also creates new requests

Question

Here is what I am looking for. Refer this image

Step 1: My app sends post a request & the server (3rd party) receives it Step 2: The third party server sends a response

I have achieved step1 & step 2 using wiremock (by stubbing the response)

Step 3: The thrid party should now send a new post request back to my app.